Document FR-2 873 212 proposes a method of fabricating a vision-correcting lens that fully incorporates a transparent optical insert.
The vision-correcting lens has a front face and a rear face and light beams emitted by an optical element of a light beam generator system are introduced into said lens via an inlet surface thereof and they directed towards the eye of the wearer in order to enable an information image to be viewed.
The light beams are reflected between the two reflection faces of the transparent optical insert, the insert being constituted by a light guide.
The information image is corrected by adjusting the focusing of the image on the light beam generator system, when the configuration of the optical insert makes that possible.
Since the information light path does not pass through the front face of the eyeglass lens, the optical correction available on the information image path is equal to the power of the rear face only. The optical correction available on the path of the information image therefore does not correspond to the vision correction that has been prescribed for the wearer. The correction deficit is compensated by changing the focusing of the generator system.
Document FR-2 872 586 describes in greater detail that type of ophthalmic display that enables the information image to be adjusted by focusing the optical beam generator system.
The ophthalmic display is fitted with a device for adjusting focusing by adjusting the length of the light beams.
The light beams are emitted from a miniature screen placed in a housing that is situated behind the rear face of the lens.
The adjustment device comprises a stationary plate supporting a miniature lens. The stationary plate is also connected to the miniature screen via an adjustable moving connection.
However, the housing in that type of device that includes an adjustment system is bulky and gets in the way of the wearer of the ophthalmic display.